Slow-release GnRHa treatment prevented atresia during vitellogenesis and induced ovulation of captive wreckfish (Polyprion americanus)
The potential of wreckfish (Polyprion americanus) to breed in captivity was examined. Ovarian activity varied seasonally, with vitellogenesis beginning in November and ending in May. Slow-release implant with gonadotropinreleasing hormone agonist (GnRHa) prevented atresia, and both GnRHa injections or implants at the end of vitellogenesis triggered ovulation after 7 days. Spontaneous spawning was obtained only in one female, and the few eggs produced were of poor viability. Manual stripping and artificial fertilization produced viable gametes and embryos. Therefore, present captivity conditions inhibited final oocyte maturation (FOM) and spawning, but not vitellogenesis and spermatogenesis. GnRHa treatments stimulate FOM and ovulation of viable eggs.